1. Field of Invention
This invention relates to a combination sleeve and bracket used to install and protect flexible tubing during and after building construction.
2. Background of the Invention
Flexible tubing is often installed in the new construction or renovation of residential or commercial buildings. An example is a refrigerant line-set, which is typically installed to interconnect split system air conditioning equipment. Flexible tubing may also be used in plumbing or fire sprinkler systems. The refrigerant line-set is probably the most prevalent usage of the invention. A line-set generally consists of two lines of copper tubing. The smaller of the two, the liquid line, is usually not insulated. The larger suction line is typically insulated. The purpose of the line-set is to tie together an outdoor air conditioner or heat pump to an indoor coil or air handler. Liquid and vapor refrigerant is pumped through the line set. The line-set is often routed through an attic or floor/ceiling assembly and then turned down into an outside wood or metal stud wall. Within generally 12″ to 24″ of the floor, the line-set turns and penetrates the outside wall siding.
The line-set is usually installed during the “rough” framing portion of the project. At this time there is usually some form of insulation board, particle board, plywood, etc. that is installed on the outside of the “studs”, or vertical framing members. However, very often the final building siding is not installed at this point. Examples may include lap siding, sheet siding, brick, stucco, stone, etc. These are installed over the insulation board etc. at a later date in the construction process.
The usual installation of the line-set involves cutting a hole in the interior sheathing and installing the tubing through the hole at an approximate 20 to 75 degree angle. The tubing typically cannot be bent a full 90 degrees because it will “kink”. A kink is a compression of the inside area of the tubing when it is bent to too sharp of an angle. The same process occurs when a drinking straw is bent too sharply. With many types of tubing, including copper, a kink usually cannot be repaired. It must be replaced.
After the installation personnel have installed the tubing at the correct angle, the tubing terminates outside the wall anywhere from a few inches to a few feet from the wall. The tubing is left at this point in the construction process without connecting it to an air conditioner or heat pump. The equipment is usually set later in the “trim” stage of the project after the exterior siding is installed. Quite often, later in the construction project, personnel from another subcontracting trade on the project will manually move the protruding tubing on the outside of the building. A major example is the exterior siding subcontractor. Brick masons will often move the tubing to a position where it protrudes from the wall at a 90-degree angle. This makes the bricks easier to install. A problem is created at that point because the tubing is generally kinked inside the wall. This problem may not be discovered until the project is almost complete. Since the tubing is kinked, the air conditioning system will not operate correctly. At this point in the project, the exterior sheathing has already been installed as well as the dry wall on the inside. The interior paint and carpet, as well as exterior paint are usually complete at this time. The only way to repair the kink is to cut either the dry wall on the inside or the exterior siding. This potentially causes other problems. To repair the kink, the kinked portion of the tubing must be cut out and a new 90-degree elbow, coupling, new tubing etc. are installed. These are soldered using high temperature torches. Since there is typically flammable material in close proximity such as wood framing, insulation, and exterior sheathing, this presents a significant fire hazard.
There is quite an expense involved when repairing this problem. This may involve repairs to drywall, siding, brick, interior paint, exterior paint, carpet cleaning and of course the tubing itself There is also quite an expense to repair the problem because in order to open the copper tubing, any refrigerant must be recovered in accordance with the Environmental Protection Agency guidelines. The tubing is usually leak tested. Then the system must be recharged with refrigerant.
Although other personnel on the construction project usually cause the above problems, sometimes the personnel that install the tubing cause the problem. This can happen without the knowledge of the installer because the suction line tubing is generally insulated with pipe insulation. This shields potential kinks from view. Because the tubing is installed through a rough-cut hole in the outside wall, there is nothing to regulate the angle of the bend in the tubing. If this problem occurs, it has the same results as when other personnel on the project cause the problem.
Quite often the line set is installed through a hole in the outside sheathing with nothing covering the hole from view. This can be visually unappealing. One common practice is to install a hooded piece of sheet metal or plastic over the tubing on the outside of the exterior sheathing. This hood resembles wall caps commonly used for air exhaust applications such as exhaust fans or clothes dryer vents. These covers are installed after the exterior sheathing and have no effect of protecting the copper from being kinked. They are mainly installed for their appearance or possibly to prevent water leaks.
Another common problem with the exterior wall penetration of tubing is that rainwater can enter through the hole. The hole in the sheathing is usually caulked or spray foam is applied around the tubing. The pipe insulation around the tubing makes it difficult to have a solid surface to apply the caulking or foam. In addition, the caulk foam, or insulation may degrade over time and cause water infiltration at a later date.